"We expect Microsoft to rethink its pricing strategy for RT in the coming weeks," he said, adding that getting manufacturers on board would probably mean "dropping the price by 60 per cent".

The report said tablet sales were up 75 per cent overall in the fourth quarter to 46.2 million units, bringing the full-year total to 114.6 million.

Canalys estimated the new iPad mini made up more than half of Apple's tablet sales, and that Apple's overall share of the tablet segment fell to 49 per cent, becoming the first quarter it has not controlled more than half the market.

"Apple timed the launch of the iPad mini well," said Pin-Chen Tang of Canalys.

"Its success proves there is a clear demand for pads with smaller screens at a more affordable price. Without the launch, Apple would surely have lost more ground to its competitors."

Canalys said Amazon's worldwide shipments grew 18 per cent in the quarter to 4.6 million units, as it expanded the Kindle Fire and launched in markets outside the US.